PRESSURE AND TEMPERATURE RECORDER

Transcription

1 PRESSURE AND TEMPERATURE RECORDER 1. APPLICATIONS 2. OPERATING FEATURES 1.1 Pressure and temperature recorders provide a permanent record of static pressure and flowing temperature which is useful: - for local tests (networks, pipes, plants) - for correcting gas volumes or for process applications. 2.1 Roll chart - Operating width: 100 mm. - Standard feed speed: 20 mm/h or 2 mm/h. - Linear range.

2 2.2 Chart driver 3.2 Temperature 2.3 Case - Mechanical clock (8 or 30 days term winding up). - Quartz controlled motor battery operated (1,5 V battery intrinsically safe for hazardous areas Certificate CESI 03 ATEX 142 II Ex ia II CH4). - Electric motor, 220 V ac power supply (for safe areas). Die-cast aluminium case, water and dust proof (IP54), for mounting on panel or 2 bracket. Front dimensions: 288 x 432 mm. - High sensitivity gas filled element in carbon steel. - On request : bulb, capillary and its protective sheath, thermowell in stainless steel AISI Standard capillary lenght: 5 m. - On request: 10/15/20/25 and over capillary lenght. - Ranges : -10 C +40 C -20 C + 60 C -20 C + 80 C Other ranges are available on request. - Accuracy: ± 1% of range. - Process connection : 3/4" NPT M. 3. TECHNICAL FEATURES 4. WARNING 3.1 Pressure 4.1 Pens - CuBe2 alloy bourdon tube for medium and high pressure. 0 1 / 1,6 / 2,5 / 4 / 6 / 10 / 16 / 25 / 40 / 60 / 100 / 160 / 200 bar Accuracy: ± 1% of range. - Bronze bellow for low pressure / 60 mbar. Accuracy: ± 2% of range. Recorders can carry up to three writing pens. In case of multiple simultaneous recordings the pens and the arms holding the pens are of different lengths to allow the necessary overlap (fig. 1). Pens are fibre tip disposable with self-writing of about 400 m. Slip off the old ink out pen and insert the new one, taking care to advance that along the arm of the pen until the appropriate stop. - Stainless steel AISI 316 bellow for low pressure / 160 / 250 / 400 / 600 mbar Accuracy: ± 2% of range. Fig. 1

3 The pens are made in different colors (red, blue, green as the colors of recordings) and bear on the side the symbol which identifies the length: this is for the demand for spare parts. 4.2 Roll chart driver (Fig. 2) It consists of a series of rollers, mounted between two sides that play a supporting and fixing function, on which the roll chart unfolds and wraps, and of a clock which determines the movement. Between the conveyor roller and the rewinding roller the roll chart runs on a writing plate that serves as support for the pens. To activate the mechanical chart driver, lead to "M" the lever (2) to M. To stop that, lead the lever back to "A". The winding up of the clock is obtained by raising and lowering the lever several times (1). To avoid damage to the winding up spring, do not force the winding up too much. The electric version has an ON OFF switch instead of the lever (1). In the 1,5 V battery power supply version the start and stop are given by inserting or removing the plug of the battery located in its housing (2). To insert the roll chart, proceed as follows : - Unscrew the knurled knob (3), located on the right side, but without removing that. - Unthread the re-winding roller (4), pushing that axially to the right, - Overturn the writing plate, pulling out the two knobs (5), - Insert the roll chart pushing it right into place, - Lift the paper guide (6), - Put the roll chart on the two moving guide rollers (7), under the following fixed roller and then under the paper guide and therefore on the conveyor roller, - Lower the writing plate and then the paper guide, - by working the knurled discs of the toothed roller by hand (9), move the chart down, cut the end of the chart and insert it under the tongue (8) of the re-winding roller, - after two turns of re-winding, position the roller and adjust the tension of the paper and the time, always working on the knurled discs of the conveyor roller. Fig. 2

4 5. MOUNTING INSTRUCTIONS 5.4 Pressure acquisition 5.1 Panel mounting Installation is done with the simple insertion of the instrument and with the tightening of the circular plates on special screws. The entrance of the pressure into the instrument is from the fitting ½ "NPT F on the back of the enclosure, using a AISI 10x1 mm tube (fig.5) It is good practice to interpose, before entering into the device, and in a lowered position, the barrel to collect and drain the condensation of gas. At the entrance of the barrel a valve has to be secured. All the connections between the different parts shall be made with compression fittings: you should make sure of their perfect seal with leak detectors, after putting pressure on the instrument. Fig Wall mounting This assembly is well suited for sole instruments or with limited space. On the wall a suitable frame must be installed, or n. 4 brackets, with holes for the screws of the instrument. It is appropriate that the distance between the wall and the instrument is at least 400 mm Bracket mounting This assembly is well suited to equipment mounted on a skid or when the recorder is placed in close proximity to other devices. Fig. 5 Fig. 4

5 5.5 Temperature acquisition The recorder has its own thermometric element that comes out the back of the case. The thermometer element is a single whole constituted by the sensing bulb, the thermowell, the capillary and the tube inside the housing. The capillary has a thickness of 3 mm and, as always protected by a special sheath, requires special attention during the installation of the thermometric element. A strong stretching or a sharp bending of the capillary could damage it, in which case the entire element should be replaced. The recorder will be installed correctly in the right vicinity of the pipeline in order to guarantee an easy unrolling of the capillary from the instrument to the insertion point of the bulb. The operations to be performed will be: - to remove the bulb from the thermowell after unscrewing the nut, - to weld the sleeve in the set position on the pipe and then put in the thermowell and screw-tight. - to insert the bulb in the thermowell, after pouring a thin layer of mineral oil which ensures the best thermic connection, - to lock the bulb with the nut.